Challenges and Future Directions of Geotechnical Engineering Education in Response to Emerging

Multi-scale Soil-Environment Problems

C. Arson, Georgia Institute of TechnologyG. Buscarnera, Northwestern University

Outline

1. Introduction – 2014 Geotechnical Education Workshop in Cambridge, UK

2. Pre-requisites to undergraduate geotechnical engineering

3. Current challenges and proposed alternatives

4. Use of new technologies

5. Conclusion – What should we do?

2014 Workshop Description• Workshop in Cambridge (UK), Sept 5-6, 2014

• Funded by the U.S. National Science Foundation

• Chairs: C. Arson (Georgia Tech), G. Biscontin (Univ. Cambridge), G. Buscarnera (Northwestern Univ.), J.C. Santamarina (Georgia Tech, now KAUST), C. Viggiani (L3SR Grenoble)

• 44 participants = 20 U.S. + 24 E.U. = 19 F + 25 M = 13 Senior + 19 Junior + 12 Students

2014 Workshop GoalsEmerging geotechnical areas are at the intersection between mechanics,

physics, chemistry, biology, thermodynamics, and mathematics…

• How should future geoengineers be educated to navigate between different bodies of knowledge?

• What are the essential skills that need to be acquired at the undergraduate level? at the graduate level?

• Which educational activities will best convey these skills?• How should these activities be integrated into current Civil Engineering

curricula?

1. Earthquake engineering and soil cyclic behavior 2. Bio-THCM couplings – fundamental processes 3. Bio-THCM couplings – geo-structures 4. From grain-scale mechanics to large-scale mechanisms 5. Ground improvement for environment protection

Pre-requisites to undergraduate geotechnical engineering

• In the United States, most Civil Engineering undergraduate curricula offer only one course in Soil Mechanics.

• In Europe and in the United States, the first course taught to engineering students in geotechnical engineering has not changed significantly in contents during the last few decades: it covers soil gradation, soil compaction, steady laminar flow and Darcy’s law, one-dimensional consolidation theory and soil shear strength.

• Future engineers need to master new experimental and theoretical skills that will allow them to solve multi-scale, multiphysics problems, and make recommendations for safe and sustainable design.

Pre-requisites – Multiscale Problems

Alternative perspectives on the direct shear test.

• Current understanding of soil strength: relationship between confining pressure and strength analogous to the relationship between the normal force and the resistance to sliding of a block resting on a surface.

• The use of the term angle of internal friction strongly implies that it is sliding friction that drives the strength-dependent nature of soil block (e.g., Bolton, 1979; Knappett and Craig, 2012).

• Photoelastic experiments (e.g. de Josselin de Jong & Verrujit, 1969), micro computed tomography images (e.g. Hasan & Alshibli, 2010), and DEM simulations (e.g. Rothenburg & Bathurst, 1989; Masson and Martinez, 2001) indicate that in a granular material a subsets of highly stressed particles, transmitting relatively high contact forces, form clusters and align to form strong force chains.

The relationship between inter-particle friction and the angle of shearing resistance (’) is non linear, and that beyond a certain value increases in interparticle friction do not result in increases in ’ (Thornton, 2000; Ni et al., 2000).

Pre-requisites – Multiphysics Problems

• In Europe and in the U.S, physics, chemistry, geology, mechanics are taught early in the curriculum. Coupled processes, which are more complex, are not covered.

• Basic soil mechanics is taught within a time-constrained framework, which does not allow freeing up time for teaching coupled processes.

• There is a lack of teaching material on coupled processes, and a lack of experience in training young engineers to soil-environment design challenges.

Pre-requisites – Design

• Engineering demand beyond classical geotechnical structures and simplistic strength, stiffness, and porous media concepts summarized by 20th century’s Terzaghi, Peck, Holtz, Kovacs…

• New challenges on subsurface environmental protection, ground improvement, engineered barriers, sustainability, energy production.

• What alternatives can we propose to classical geotechnical education at the undergraduate level?[see challenges and alternatives]

• How can we address the needs of the industry?Proposal: Survey to develop sample curricula that address the needs of industry, while relying on basic principles and theory and providing opportunity to connect with other subjects.

Challenges and proposed alternatives

Revisiting the curriculum roadmap

• Incorporate all the contents devoted to elementary processes and shared by different engineering departments in preliminary courses (e.g., physics, mathematics, material science, transport phenomena, geology, etc.).

• Those elementary processes are meant to become prerequisites for the soil mechanics courses.

• Time will be spared in current soil mechanics courses, which will allow the introduction to these coupled problems.

Challenges and proposed alternativesOpen-ended geotechncial projects for undergraduate students.

• Goal: gain fundamental knowledge on heat transfer, water transfer and coupled thermo-mechanical soil and rock properties.

• Learning objectives: (1) split problems into partially coupled problems; (2) propose a timeframe to achieve projects.

• Review of existing projects: period of the project, time at which the project comes in the curriculum, number of earned credits, involvement of industry and deliverables on which students are evaluated.

• Implementation: at least a year, mentoring strategy that involves industry partners, site and plant visits, rotating project topics that ensures continuity for students and industry partners

• Optional features: include collaborations amongst students across departments and across generations (e.g. first-year, second-year students, etc.). See VIP @ Georgia Tech.

Challenges and proposed alternativesLaboratory activities

• Problem: difficult or economically unfeasible to provide an appropriate practical and hands-on experience to supplement theoretical class time learning

• Challenges: large classes, limited teaching resources, onerous health and safety requirements, lack of suitable laboratory space & equipment and ineffective use of laboratory sessions

• Alternative: incorporating open-ended design-based experiments in the laboratories, with examples of geotechnical concepts that are well suited to laboratory experiments

Challenges and proposed alternativesRevisited physical models in soil mechanics

• Goal: focus on the granular nature of soil as an aid to teaching some of the fundamental principles of soil mechanics

• Implementation: low cost and reasonably straightforward to perform with soil grains and soil grain analogues, e.g., rice, cornflakes, coffee, and coins

• Phenomena: undrained to drained behaviour; normal compression and swelling; 1D versus 3D deformation; granular friction, strength and dilatancy.

• Applications: soil reinforcement; planar seepage through embankments / under retaining walls

• Links with theory: include prediction before the experiment, measurement (including selection of data to measure) and comparison with soil mechanics theory using short calculations related to the phenomena under consideration

• Links with numerical methods: compare experimental results with numerical predictions (e.g. via discrete element) or with imaging data (e.g. via tomographic or photoelastic methods).

New technologies – Media & Big Data

Virtual tours of practice and research worldwide

• Goals: (1) Make students aware of the latest ‘technology’ being developed within geotechnical engineering research; (2) Provide exposure to different systems of application of such technology around the world; (3) Foster global awareness.

• Implementation: international collection of short video presentations based on current research projects and virtual tours of innovative construction projects from around the world, in each case highlighting the importance of geotechnical engineering to the work.

• Assessment: pre- and post-survey questionnaires used to quantify changes in students’ perception of geotechnical engineering in terms of awareness of global issues and interest in seeking a career specializing in geotechnical engineering.

• Impacts: the video archive can be a live resource for academics worldwide, being continually updated as research and practice evolve.

New technologies - Communities

• Topical communities: ALERT (Europe); NEES (U.S.), IACMAG (worldwide)

• Geotechnical societies: CFMR (Europe); ASCE & ARMA (U.S.); ISSMGE (worldwide)

• Global platforms and exchange tools: Dropbox, Mendeley, Facebook, Google +

Conclusion – What should we do?

• What is the future of geotechnical engineering?

• What is our responsibility as educators? As scientists?

C. Arson, G. Buscarnera, 2014. Book of Abstracts Report from: International Workshop on Education of Future Geotechnical Engineers in Response to Emerging Multi-scale Soil-Environment Problems, SmarTech Electronic Archive,URL: http://hdl.handle.net/1853/52656